Katie Couric’s visit last week to Baltimore’s WMAR proved at least one thing: She is serious about making her new daytime talk show, “Katie,” a winner. She did not do such intense promotion in the summer of 2006 even when she was about to debut as anchor of the “CBS Evening News," one of the most prestigious -- or at least historic -- jobs in television.

And that kind of commitment from her means the competition in one of the most hotly contested time periods in local TV is going to be even fiercer this fall when her syndicated show debuts.

Come Sept. 10, the former star of network morning TV is going to find herself up against Ellen DeGeneres, Ricki Lake, Judge Judy (Judith Sheindlin) and WJZ news anchors — all fighting for a slice of the Baltimore pie Oprah Winfrey left behind.

“Ellen” didn’t have a bad year reaching her target audience in Oprah’s old time period on WBAL, but she failed to hold a substantial portion of Oprah’s overall audience. As a result, the crucial 4 p.m. time period is still very much up for grabs.

Here’s an indication of how unpredictable that 60 minutes can be: The latest ratings show “Judge Judy” attracting more overall viewers than “Ellen” while finishing second to the newscasts from WJZ, Baltimore’s CBS-owned station. Coming in midsummer, the July ratings period isn’t considered one of the year’s most important, but it nevertheless underscores how no one in the market is willing to give an inch or take a day off in this battle.

“We put ‘Judge Judy’ on Fox 45 at 4 and 4:30 p.m. to take advantage of the void left from the departure of Oprah,” says Bill Fanshawe, general manager of WBFF and WNUV. “In a short period of time, ‘Judge Judy’ has become either the No. 1 or No. 2 program in households and key women demographics based on the July 12 Nielsen sweep period. We expect ‘Judge Judy’ to be the clear winner in the fall, as viewers continue to find her.”

Winning it all at 4 seems overly optimistic for “Judge Judy,” but the program has already demonstrated that it will find fans and make money for WBFF. No doubt about that.

Meanwhile, on WNUV, “We are picking up Ricki Lake since she has the most broad-based appeal out of the new programs, similar to Oprah,” Fanshawe says.

And Lake might still have a bit of extra Baltimore appeal: She was John Waters’ original Tracy Turnblad in “Hairspray.”

What makes the time period so important is the way a winning show can drive viewership into the 5 p.m. and 6 p.m. local newscasts, giving a station three hours of revenue boosts instead of just one.

And stations that air local news don’t have to share money with syndicators — they get to keep it all. That has made WJZ’s strategy of going to local news at 4 p.m. a winner in revenue even when it finished a distant second to “Oprah.” WJZ wasn’t splitting the ad revenue with anyone else, so it could afford to take in less than “Oprah” in ad sales and still turn a profit.

“We have been vigilant in focusing for more than a decade now on a counterprogramming strategy at 4 o’clock,” says Jay Newman, general manager of WJZ. “And that involves not being in the entertainment business. Instead, we have focused on providing a newscast that is 52 weeks a year, five days a week, live, locally oriented with what’s going on that day as the leadoff to the three-hour news block.”

Because of that, Newman says, the change at other stations doesn’t matter to WJZ.

“Despite all the programming changes — and there have been many of them in that time period — we have been successful regardless of what the competition is,” he says. “We have consistently been No. 1 or No. 2 virtually every month, year in, year out, and that’s what we’re going to continue to focus on in the fall. Syndicated programs come and go, but the news is there live every day. It’s produced fresh and there are no repeats.”

WBAL General Manager Dan Joerres says his station is definitely in the entertainment business with “Ellen” and that “she’s a good fit” for the station.

“We’re thrilled with Ellen,” he says. “We really like her. She’s kind of coming into her own on that show. Seventy percent of the women who watch her are homeowners. She’s got a very upscale audience. It’s a relaxed audience that likes to be entertained.”

In the last May sweeps, the most important recent ratings period to date, “Ellen” did finish No. 1 in the key demographic of viewers 25 to 54, with 20,900 viewers versus WJZ’s second-place total of 16,800. Those are numbers that will translate directly to dollars, as most TV ad sales are made on just such demographics.

But if Couric and her executive producer, former NBC Universal chief Jeff Zucker, are going to find viewers anywhere in the Baltimore market, it would look as if those upscale homeowning women watching “Ellen” are the most likely candidates. Although some of WJZ’s news viewers might also be induced to switch if Couric’s show is as off-the-news as she promises.

“I think there's an opportunity for a deeper conversation about a lot of things that happen in the news, and I think this show will provide an outlet for that,” she told me last week in an interview at WMAR.

“Who knows [how ‘Katie’ will do]?” Joerres says. “She has a great executive producer, so you would think there’s a good plan [for the show]. … I think we’re seeing that people are still trying to find their Oprah replacement. You know, whether it’s Dr. Oz or the Ellens of the world or Dr. Phil or any of those people. Who satisfies their need and fills that void?”

Bill Hooper, general manager at WMAR, agrees that the void exists, but he thinks his host is the one to fill it, not Ellen.

“The biggest opportunity for Katie is that since Oprah has left the airwaves, no one has filled that void for a smart, informative women’s TV kind of show,” says Hooper.

“There’s nothing wrong with ‘Ellen’ or the other 4 o’clock shows, but no one has really come up with that same kind of [Oprah] formula,” he adds.

“Not that we think Katie’s going to be Oprah. I don’t think you’ll ever see another Oprah again. But we do think, No. 1, there’s a void there. And No. 2, she just has such huge name recognition and she was so popular on the ‘Today’ show, that if she comes back in that fun fashion and that personality shows through, which she wasn’t able to do on the ‘CBS Evening News,’ she could be successful leading right into the news for us.”

Viewers benefit when the competition reaches this level and performers like Couric join the fray.

But in the end, the larger cultural story might be that void Oprah left behind — and the fact that the TV industry still has not found a way to give viewers what she did.